A Tunisian foreign ministry spokesman said there had been "disagreements" at a preliminary meeting of Arab foreign ministers over issues to be discussed.

They included plans to relaunch a peace initiative to Israel, and proposals for reforms in the region.

Tunisia said it regretted postponing a summit "on which Arab and international opinion has pinned great hopes".

Arab leaders had hoped to use the conference to relaunch a peace initiative with Israel, proposed two years ago.

But after the assassination of Hamas founder Sheikh Yassin by Israel last Monday, few wanted to talk peace with the Jewish state.

US President George W Bush vowed last November not to support Arab states that rejected liberty, saying "60 years of Western nations excusing and accommodating the lack of freedom in the Middle East did nothing to make us safe".

Tunisia affirmed it would consult "Arab brothers to bring together points of view...and to prepare the best possible circumstances for the success of the summit".

Arab foreign ministers had spent Saturday afternoon looking at democratic reform proposals submitted by five Arab countries -- Egypt, Jordan, Yemen, Qatar and Tunisia.

Washington's Greater Middle East Initiative was widely criticised in the Arab world as a foreign intrusion overlooking the occupation of Iraq and the Israeli-Palestinian conflict.

The summit organisers -- Tunisia and the Arab League secretariat -- had repeatedly dismissed speculation the summit might be postponed and had reported progress on both Iraq and on democratic reform in the Middle East.